Flexible plastic films have come into wide-spread use as an insulating or barrier material. Transparent flexible plastic films are commonly used in place of residental wooden or aluminum sash type glass storm windows.
Translucent or transparent flexible film has also been widely used in the construction trade to cover large openings during building construction to protect personnel and equipment from wind, precipitation and other inclemencies of weather. In such applications the flexible film is stretched over the opening and nailed, stapled, or fastened with battens or other means to the window frame.
These methods of affixing the flexible sheeting material to the openings to be covered or insulated have the following drawbacks and deficiencies: (1) it is difficult, if not impossible, to stretch the flexible film uniformly to remove all wrinkles when using staples or battens; (2) the film cannot be easily removed for purposes of cleaning the primary window surfaces behind the film; (3) once the film is removed it may not be in a condition suitable for re-use; (4) the primary window frame may itself be damaged by the use of nails or staples; (5) the insulating efficiency of the film is greatly reduced where only nails or staples are used to secure the film to the frame; (6) construction of a proper fitting wooden frame which is removable is expensive and time consuming; (7) the appearance of the film affixed directly to the window frame or to a crude fitting wooden frame is not aesthetically pleasing, especially for residential window use.
Using the frame structure of our invention the above-mentioned drawbacks to the use of flexible film are eliminated and an aesthetically pleasing frame supporting a tautly stretched transparent flexible film can be quickly and easily constructed. In its preferred embodiment the film covered supporting frame structure is especially adaptable as a substitute for more expensive conventional wood or aluminum storm windows in residential use. It is not only lightweight and easy to install, it may be readily removed for cleaning or maintenence of the windows and frames, and to provide summer ventilation. Optionally, a tinted flexible film can be installed for use on the sunny side of air-conditioned rooms. The invention has the particular advantage of allowing the flexible film to be removed and re-installed or replaced without having to remove its supporting frame from the window.
The film supporting frame structure of our invention can be quickly assembled and installed using only hand tools. The structure contains no mitered joints and only reasonable manual skill is required in its construction. Moreover, the structure of our invention can be assembled from its component parts to fit other than standard size window openings and mounted to provide efficient, air-tight insulative seals.
The film supporting frame structures of our invention are also suitable for use in the construction trade. By providing the frame with sufficient cross-members, as described hereinafter, a large but light-weight structure can be made. Typically, in the construction of high rise buildings, protection of personnel and equipment is required for only several floors at a time. As electricians, plumbers and other tradesmen complete work on one floor and move up through the building, the frame structure can be easily removed and re-installed above. Use of the frame structure of our invention results in the saving of manpower and material since there is no need to construct temporary wooden frames or to discard film material which is damaged during removal and re-installation. As it will also be appreciated from the detailed description below, the frame structure of our invention can be readily disassembled, without damaging its interchangeable component parts, and transported for re-assembly in a different size at a different location.